Structure of wadded-up seat trim cover and method of manufacturing wadded-up seat trim cover

ABSTRACT

A structure of wadded-up seat trim cover, having a plurality of trim cover pieces sewn together at one end, each composed of a wadding member and a skin member, includes a bonded portion formed by bonding the skin member to the wadding member made shorter than the skin member, at a position remote, by a prescribed distance, from the end of the wadding member overlapping the skin member; a first sewn portion formed by bending that portion of the skin member, not overlapping the wadding member, along the end of the wadding member and then by sewing the portions of the adjacent skin members together; and second sewn portions formed by bending each end of the adjacent skin member to the back of the trim cover piece at the first sewn portion and then by sewing the adjacent skin members together at overlapping portions.

CROSS REFERENCE TO RELATED APPLICATIONS

This is the U.S. national stage of application No.PCT/JP2015/063472dated May 11, 2015. Priority under 35U.S.C. §119(a) and 35 U.S.C.§365(b) is claimed from Japanese Patent Application No. 2014-199158,filed Sep. 29, 2014,the entire contents of which are incorporated hereinby reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a structure of wadded-up seat trimcover and a method of manufacturing wadded-up seat trim cover (a surfacestructure of wadded seat which includes a trim cover covering a seatpad, and also to a method of manufacturing wadded-up seat which includesa trim cover covering a seat pad) (a skin structure of sheet withwadding material and a manufacturing method of sheet with waddingmaterial).

2. Description of the Related Art

A vehicle seat comprises a seat cushion and a seatback, each including aseat frame (a seat cushion frame or a seatback frame) which is askeleton member, a seat pad (foam member) made of, for example, urethanefoam, and a trim cover (surface member) which is composed of a pluralityof trim cover pieces sewn together at one end and which is shaped like abag. The seat pad is mounted on the seat frame, and the trim covercovers the seat pad. The vehicle seat is thereby provided.

Trim covers are known well, which excel in cushioning property ordecorativeness and may therefore impart a luxurious feel to the vehicleseats. See, for example, Japanese Patent unexamined PublicationJP2007-289284A and Japanese Utility Model unexamined PublicationJP03-094200Y. For instance, a thin wadding member is laid on the back ofa trim cover made of, for example, synthetic leather, enhancing thecushioning property of the trim cover. Further, two trim cover piecesmay be sewed at abutting ends, single-stitched or double-stitched,thereby giving the trim cover decorativeness.

Japanese Patent unexamined Publication JP2007-289284A, for example,discloses a trim cover for the head rest or arm rest of a vehicle seat.The trim cover has trim cover pieces, each trim cover piece is composedof a skin member and a wadding member. The skin member and the waddingmember are chain-stitched at one end, achieving edge linking and formingan integral component.

The sewn portions of the trim cover strips are made by sewing two trimcover strips overlapping each other, without sewing the bent-backportions that extend for a specific distance from the ends of the trimcover strip. The ends of the trim cover pieces are bent back to the backof the trim cover piece, can open to the left and right, respectively,around the sewn portions of the trim cover strips and are sewn at thebent-back portions.

This structure of the trim cover piece for the head rest or the like canbe applied to the trim cover piece for the seat cushion or the seatbackof the vehicle seat.

Japanese Utility Model unexamined Publication JP03-094200Y discloses atrim cover for the seat cushion of a vehicle seat. The trim cover pieceof this trim cover is composed of a skin member, first and second coremembers, and a wadding member bonded to the entire surface of the skinmember by means of lamination. The end of the trim cover is clampedbetween the two core members, and is sewn to the core members. The firstcore member is arranged above the end of the trim cover, and the secondcore member is arranged below the end of the trim cover. The first andsecond core members are sewn to the end of the trim cover, forming sewnportions. At the sewn portions, the trim cover piece is bent back,covering the first core member and the sewn portions.

Patent Literature 1: Japanese Patent unexamined PublicationJP2007-289284A

Patent Literature 2: Japanese Utility Model unexamined PublicationJP03-094200Y

In the structure disclosed in Japanese Patent unexamined PublicationJP2007-289284A, the skin member and the wadding member arechain-stitched at end, achieving edge linking and forming an integralcomponent. This improves the outer appearance of the trim cover.Further, the skin member and the wadding member form an integralcomponent easily, not by bonding the wadding member to the entiresurface of the skin member, but by sewing only. Since the skin memberand the wadding member are chain-stitched at one end, the skin membershifts only a little from the wadding member even if the occupant moveson the seat cushion.

However, the stiches on the end of the trim cover piece are exposed atthe upper surface of the bent-back portion of the trim cover piece.Inevitably, the stiches may therefore hitch or rub the occupant as hesits or moves on the vehicle seat. Consequently, the sewn portions maybe unraveled or severed, impairing the outer appearance of the trimcover.

In the structure disclosed in Japanese Utility Model unexaminedPublication JP03-094200Y, the trim cover piece is bent back, coveringthe sewn portion of the trim cover piece and first core member. The trimcover piece therefore conceal unraveling or severing of sewn portions,if any, at the end of the trim cover piece. Hence, the outer appearanceof the trim cover would not be impaired.

However, since the trim cover piece conceals the sewn portions, the sewnportions cannot achieve any design improvement of the trim cover.Further, since two core members must be used, the trim cover piece iscomposed of more components than otherwise.

An object of this invention is to provide a structure of wadded-up seattrim cover, which is manufactured by sewing and has a better outerappearance without increasing the number of components and withoutunraveling or severing of the sewn portions.

Another object of this invention is to provide a method of manufacturingwadded-up seat trim cover, which can manufacture a trim cover having abetter appearance by means of sewing without increasing the number ofcomponents and without unraveling or severing of the sewn portions.

SUMMARY OF THE INVENTION

In the present invention, the wadding member is shorter than the skinmember. The wadding member is bonded to the skin member at a positionremote from its end by a prescribed distance. Then, the skin member isbent along the end of the wadding member, forming two adjacent trimcover pieces. Two trim cover pieces are sewed together, providing a seatcover (i.e., trim cover).

More precisely, according to one aspect of the embodiment of claim 1, astructure of wadded-up seat trim cover for covering a seat pad, having aplurality of trim cover pieces sewn together at one end, each composedof a wadding member and a skin member backed with the wadding member,the structure includes a bonded portion formed by bonding the skinmember to the wadding member made shorter than the skin member, at aposition remote, by a prescribed distance, from the end of the waddingmember overlapping the skin member; a first sewn portion formed bybending that portion of the skin member, which does not overlap thewadding member, along the end of the wadding member and then by sewingthe portions of the adjacent skin members together below the adjacentwadding members; and second sewn portions formed by bending each end ofthe adjacent skin member to the back of the trim cover piece at thefirst sewn portion and then by sewing the adjacent skin members togetherat overlapping portions that clamp the first sewn portion.

According to one aspect of the embodiment of claim 4, a method ofmanufacturing a wadded-up seat trim cover for covering a seat pad,having a plurality of trim cover pieces sewn together at one end, eachcomposed of a wadding member and a skin member backed with the waddingmember, the method includes a bonding step of bonding the skin member tothe wadding member made shorter than the skin member, at a positionremote, by a prescribed distance, from the end of the wadding memberoverlapping the skin member, thereby forming a bonded portion; a firstsewing step of bending that portion of the skin member, which does notoverlap the wadding member, along the end of the wadding member and thensewing the adjacent trim over pieces below the adjacent wadding members,thereby forming a first sewn portion; and a second sewing step ofbending each end of the adjacent skin members to the back of the trimcover piece at the first sewn portion and then sewing the adjacent skinmembers together at overlapping portions that clamp the first sewnportion, thereby forming second sewn portions.

In the invention according to claim 1, a groove having a depthcorresponding to the sum of the thickness of the skin member and thethickness of the first wadding member is provided between the two trimcovers pieces. The depth is approximately equal to the thickness of thewadding member. First and second sewn portions are located below thebottom of the groove, namely the upper surface of the skin member (i.e.,trim cover piece), by a distance equivalent to the thickness of thewadding member. Therefore, the first and second sewn portions would nothitch or rub the occupant as he sits or moves on the vehicle seat, andthe sewn portions would not be unraveled or severed. Further, the secondsewn portion, which is seen from the upper surface of the trim cover(i.e., trim cover pieces) through the groove, imparts decorativeness anda good outer appearance to the trim cover.

Moreover, the wadded-up seat trim cover need not have core members, andthe number of components does not increase.

In the invention according to claim 4, a groove is provided between twotrim cover pieces in the first and second sewing steps only, and thefirst and second sewn portions are positioned on the bottom of thegroove, which lies below the upper surface of the skin member (i.e.,trim cover pieces) by the distance approximately equivalent to thethickness of the wadding member. Hence, a wadded-up seat trim cover canbe manufactured in a simple method having a few steps, without usingadditional components such as core members. In the trim cover, the firstand second sewn portions would not hitch or rub the occupant as he sitsor move on the vehicle seat, and the sewn portions would not beunraveled or severed. The trim cover therefore has a good outerappearance.

Since no additional components such as core members are used, the numberof components would not increase.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a vehicle seat having a structure ofwadded-up seat trim cover, according to embodiments of the presentinvention;

FIG. 2A is a magnified sectional view taken along line 2A,4A-2A,4A shownin FIG. 1, showing the structure of wadded-up seat trim cover, accordingto the embodiment (Embodiment 1) of the present invention;

FIG. 2B to FIG. 2D are sectional views explaining the process of backinga skin member with first and second wadding members prior to the sewingprocess, and particularly FIG. 2B shows the portions to be bondedtogether;

FIG. 3A is a schematic view illustrating the first sewn portion in thestructure of wadded-up seat trim cover, according to the embodiment(Embodiment 1) of the present invention;

FIG. 3B a schematic view illustrating the second sewn portions in thestructure of wadded-up seat trim cover, according to the embodiment(Embodiment 1) of the present invention;

FIG. 4A is a magnified sectional view taken along line 2A,4A-2A,4A shownin FIG. 1, showing the seat skin (i.e., trim cover) of the structure ofwadded-up seat trim cover, according to another embodiment (Embodiment2) of the present invention;

FIG. 4B to FIG. 4D are sectional views explaining the process of backinga skin member with first and second wadding members prior to the sewingprocess, and particularly FIG. 4B shows the portions to be bondedtogether;

FIG. 5A is a schematic view illustrating the first sewn portion in thestructure of wadded-up seat trim cover, according to the otherembodiment (Embodiment 2) of the present invention; and

FIG. 5B is a schematic view illustrating the second sewn portions in thestructure of wadded-up seat trim cover, according to the otherembodiment (Embodiment 2) of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

A structure of wadded-up seat trim cover for covering a seat pad, havinga plurality of trim cover pieces sewn together at one end, each composedof a wadding member and a skin member backed with the wadding member,the structure includes a bonded portion formed by bonding the skinmember to the wadding member made shorter than the skin member, at aposition remote, by a prescribed distance, from the end of the waddingmember overlapping the skin member; a first sewn portion formed bybending that portion of the skin member, which does not overlap thewadding member, along the end of the wadding member and then by sewingthe portions of the adjacent skin members together below the adjacentwadding members; and second sewn portions formed by bending each end ofthe adjacent skin member to the back of the trim cover piece at thefirst sewn portion and then by sewing the adjacent skin members togetherat overlapping portions that clamp the first sewn portion.

Embodiment

Embodiments of this invention will be described in detail, withreference to the accompanying drawings. FIG. 1 is a perspective view ofa vehicle seat having a structure of wadded-up seat trim cover,according to embodiments of the present invention; FIG. 2A is amagnified sectional view taken along line 2A,4A-2A,4A shown in FIG. 1,showing the structure of wadded-up seat trim cover, according to theembodiment (Embodiment 1) of the present invention; FIG. 2B to FIG. 2Dare sectional views explaining the process of backing a skin member withfirst and second wadding members prior to the sewing process, andparticularly FIG. 2B shows the portions to be bonded together; FIG. 3Ais a schematic view illustrating the first sewn portion in the structureof wadded-up seat trim cover, according to the embodiment (Embodiment 1)of the present invention and FIG. 3B a schematic view illustrating thesecond sewn portions in the structure of wadded-up seat trim cover,according to the embodiment (Embodiment 1) of the present invention.

In the drawings, arrows Fr and Rr indicate the forward and rearwarddirections, and arrows L and R indicate the leftward and rightwarddirections, with respect to the driver seated in the driver seat.

As shown in FIG. 1, the vehicle seat 10 comprises a seat cushion 12 anda seatback 14 provided at the rear end of the seat cushion 12. Aheadrest 16 is arranged on the top of the seatback 14.

The basic structures of the seat cushion 12 and seatback 14 are wellknown in the art. The seat cushion includes a seat cushion frame (notshown), a seat pad 12-1, and a trim cover 20. The seat cushion frame isshaped like letter U and composed of left and right side frames and aconnecting pipe connecting the front ends of the side frames. The seatpad is made of foamed material such as urethane foam and is mounted onthe seat cushion frame. The trim cover has air permeability and coversthe seat pad. Similarly, the seatback 14 is formed by first mounting aseat pad on a seatback frame and then covering the seat pad with anair-permeable trim cover.

The trim cover 20 of the seat cushion is shaped, covering the seat pad12-1, and is composed of two trim cover pieces sewn together at one end.The trim cover 20 is composed of, for example, an upper trim cover 20Upand a lower trim cover 20Lw. The upper trim cover has been made bysewing three trim cover pieces, i.e., left, center and right trim coverpieces.

At the intersection of the center trim cover piece 22 and left trimcover piece 24, for example, the center and left trim cover pieces aresewn at one end, forming a sewn portion.

How the center trim cover piece 22, one constituting member of the uppertrim cover 20Up, is formed will be explained below. The left trim coverpiece 24 sewn to the center trim cover piece 22 is formed in the sameway as the center trim cover piece.

The center trim cover piece 22 is composed of a skin member 22 a, afirst wadding member 22 b-1 and a second wadding member 22 b-2, one laidon the back of another, from the upper surface (i.e., seat cushionsurface) in the order mentioned.

The skin member 22 a is made of, for example, synthetic leather. Thefirst and second wadding members 22 b-1 and 22 b-2 are made of soft andelastic material such as polyurethane foam sheet.

As seen from not only from FIG. 2A, but also FIG. 2B, the first waddingmember 22 b-1 of the center trim cover piece is shorter than the skinmember 22 a and the second wadding member 22 b-2. The first waddingmember is interposed between the skin member and the second waddingmember. In other words, the first wadding member 22 b-1 is laid on thesecond wadding member 22 b-2, and the skin member 22 a is laid on thefirst wadding member 22 b-1. The skin member 22 a and the second waddingmember 22 b-2 are longer than the first wadding member 22 b-1, and theportion 22 af of the skin member and the portion 22 b-2 f of the secondwadding member extend in widthwise direction (i.e., leftward), beyondthe end 22 b-1 f of the first wadding member. Therefore, the portion 22af of the skin member and the portion 22 b-2 f of the second waddingmember do not overlap the first wadding member.

The skin member 22 a extends in the width direction (i.e., left-rightdirection) beyond the end 22 b-1 f of the first wadding member, bydistance X1. Distance X1 is, for example, 30 to 40 mm.

The second wadding member 22 b-2 extends beyond the end 22 b-1 f of thefirst wadding member, for distance X2. As seen from FIG. 2B, the secondwadding member 22 b-2 is shorter than the end of the skin member 22 aby, for example, the thickness Z of the first wadding member.

At the position where the skin member 22 a of the center trim coverpiece 22 overlaps the first wadding member 22 b-1, the first waddingmember is bonded to the skin member at a prescribed distance (i.e.,distance Y) from the end 22 b-1 f of the first wadding member, therebyforming a bonded portion 30. The bonded portion 30 is line-bonded,extending in the lengthwise direction (i.e., front-rear direction) ofthe seat cushion. The distance Y is, for example, 10 to 20 mm.

The portion 22 af of the skin member, which does not overlap the firstwadding member, is bent along the end 22 b-1 f of the first waddingmember, in the direction of an arrow shown in FIG. 2B. As a result, theportion 22 af overlaps the portion 22 b-2 f of the second waddingmember. More specifically, as shown in FIG. 2C, the portion 22 af of theskin member contacts the end 22 b-1 f of the first wadding member,presses the same downwards, is bent from the bonded portion 30 along theend of the first wadding member, and overlaps the portion 22 b-2 f ofthe second wadding member.

Those portions of the skin member and second wadding member, which areremote by a prescribed distance from their ends and which overlap eachother, are bent downward in the direction of an arrow shown in FIG. 2C,forming bent-back portions 22 af′ and 22 b-2 f′ as seen from FIG. 2D.

Like the center trim cover piece 22, the left trim cover piece 24 iscomposed of a skin member 24 a, a first wadding member 24 b-1 and asecond wadding member 24 b-2. The skin member 24 a of the left trimcover piece is bonded to the first wadding member 24 b-1 of the lefttrim cover piece, thereby forming a bonded portion 30. The portion 24 afof the skin member, which does not overlap the first wadding member, isbent along the end 24 b-1 f of the first wadding member. Then, theportion 24 af of the skin member is laid on the portion 24 b-2 f of thesecond wadding member, which does not overlap the first wadding member(see FIG. 2B and FIG. 2C). Those portions of the skin member and secondwadding member, which are remote by a prescribed distance from theirends, are formed bent-back portions 24 af′ and 24-2 f′. Then, the skinmember and the second wadding member, overlapping each other, are bentdownward in the direction of the arrow shown in FIG. 2C (see FIG. 2D).

The skin member 22 a and the second wadding member 24 b-2 of the centertrim cover piece and the skin member 24 a and the second wadding member24 b-2 of the left trim cover piece, all adjacent to one another, aresewn together below the second wadding member, forming first sewnportion 31 (see FIG. 3A). More specifically, the first sewn portion 31is formed by placing the center trim cover piece 22 and the left trimcover piece 24 adjacent to each other and by sewing the skin member 22 aof the center trim cover piece, the skin member 24 a of the left trimcover piece, the second wadding member 22 b-2 of the center trim coverpiece and the second wadding member 24 b-2 of the left trim cover piece,which are bend downwards, below the second wadding member.

Next, the ends of the center trim cover piece 22 (more precisely, thebent-back portion 22 af′ of the skin member and the bent-back portion 22b-2 f′ of the second wadding member), and the ends of the left trimcover piece 24 (more precisely, the bent-back portion 24 af′ of the skinmember and the bent-back portion 24 b-2 f′ of the second waddingmember), are bend back to the back of each trim cover at the first sewnportion 31. Then, the first sewn portion 31 is clamped at the ends ofthe trim cover pieces 22 and 24 so bend back. Further, the skin member22 a and the second wadding members 22 b-2 of the center trim coverpiece are sewn together, forming one second sewn portion 32, and theskin member 24 a and the second wadding members 24 b-2 of the left trimcover piece are sewn together, forming another second sewn portion 32(see FIG. 3B).

The center trim cover piece 22 and the left trim cover piece 24 are sewntogether at one end, forming the first sewn portion 31. The skin memberand the second wadding member of the center or left trim cover piece aresewn together at bent-back end, forming the second sewn portion 32.Needless to say, two sewn portions 31 and 32 are formed, by the samemethod, also at the center and right trim cover pieces.

For example, the trim cover piece 24 may be replaced by a center trimcover piece 124, and the trim cover piece 22 may be replaced by a righttrim cover piece 122, in the structures FIG. 2A and FIG. 3A. Further,the right trim cover piece 122 and the center trim cover piece 124 maybe sewn in the same way as the trim cover pieces 22 and 24. Then, thecenter trim cover piece 124 and the right trim cover piece 122 are sewnat end, forming a first sewn portion 31. The skin member and the secondwadding member of the center or right trim cover piece are sewn togetherat bent-back end, forming the second sewn portion 32.

Like the center trim cover pieces 22 and left trim cover piece 24, theright trim cover piece and the center trim cover piece are sewedtogether, forming the upper trim cover 20Up. The upper trim cover 20Upis positioned on the seat pad 12-1 of the seat cushion and extends tothe left and the right along the shape of the seat pad, covering theseat pad (see FIG. 1 and FIG. 2A).

The first sewn portion 31 is formed by sewing the skin members 22 a and24 a and the second wadding members 22 b-2 and 24 b-2 below the secondwadding members. Each second sewn portion 32 is formed by sewing theskin member 22 a or 24 a and the second wadding member 22 b-2 or 24 b-2together, with the first sewn portion clamped between the skin members.The first wadding members 22 b-1 and 24 b-1 are not sewn at the firstsewn portion 31 or the second sewn portion 32.

Since the skin members and the second wadding member are so sewn asdescribed above, a groove S is provided between the trim cover pieces 22and 24, having a depth equal to the sum of the thickness of the skinmember and the thickness of the first wadding member. The depth of thegroove S is equal to the thickness Z of the first wadding membersubstantially, since the thickness of the skin member is much thinnerthan the thickness of the first wadding member. The groove S has, forexample, a U-shaped cross section. As seen from FIG. 3B, the first sewnportion 31 and the second sewn portions 32 are positioned below theupper surfaces of the trim cover pieces 22 and 24 (i.e., surface of theseat cushion), lying on the bottom of the groove S and spaced from theupper surfaces of the trim cover pieces by the distance approximatelyequivalent to the thickness of the first wadding member.

The first sewn portion 31 and the second sewn portions 32 are positionedbelow the upper surfaces of the trim cover pieces 22 and 24, lying onthe bottom of the groove S. Therefore, neither the first sewn portion 31nor the second sewn portions 32 would not hitch or rub even if the seatcushion (more precisely, trim cover piece) warps as the occupant sits ormove on the seat. Hence, the sewn portions would not be unraveled orsevered. In addition, the second sewn portions 32 are seen through thegroove S, from above the trim cover (more precisely, trim cover pieces).The trim cover therefore has a better design effect (decorativeness)than any seat having no sewing decoration. Hence, the trim cover(wadding-up seat trim cover) can have a good outer appearance.

The trim cover pieces 22 and 24 are each composed of a skin member andfirst and second wadding members only, not requiring any othercomponents. Therefore, the number of the components constituting thetrim cover does not increase.

Moreover, since the groove S functions as the air passage at the uppersurface of the seat cushion, air conditioning can be performed in theseat cushion even if the occupant keeps sitting on the seat.

The distances X1, X2, Y and Z may be changed, thereby to change theshape of the groove S, more precisely the depth and the length (measuredin the left-right direction). This enhances design effect and thefreedom of design.

The distance Y, for example, suffices to be long enough to allow theportions 22 af and 24 af of the skin members, which do not overlap thefirst wadding member, to contact the ends 22 b-1 f and 24 b-1 f of thefirst wadding members, while pressing the same downwards, and to be bentalong the end of the first wadding member. The distance X1 suffices tobe long enough to allow the portions 22 af and 24 af of the skin membersto contact the ends 22 b-1 f and 24 b-1 f of the first wadding members,while pressing the same downwards, and to be bent along the end of thefirst wadding members, thereby to form first and second sewn portions 31and 32.

Similarly, the distance X2 suffices to be long enough to bend theportions 22 b-2 f′ and 24 b-2 f′ of the second wadding members to theback of the trim cover at the first sewn portion 31, thereby to form thesecond sewn portion 32 at the overlapped portions with the bent-backportions of the second wadding members.

As seen from FIG. 2A, the first wadding member 22 b-1 or 24 b-1 isthicker than the second wadding member 22 b-2 or 24 b-2. However, sincethe first wadding member is thicker than the second wadding member, thegroove S is deeper by the thickness of the first wadding member, andprevents unraveling at the first and second sewn portions.

Only in the bonding step of forming the bonded portion 30 and the firstand second sewing steps of forming the first and second sewn portions 31and 32, the groove S is made between the two trim cover pieces, and thefirst and second sewn portions are formed on the bottom of the groove S.Thus, a simple method having a few steps can manufacture a trim cover(wadding-up seat trim cover) which undergoes neither unraveling norsevering at the first and second sewn portions 31 and 32, and which hasa good outer appearance.

FIG. 4A is a magnified sectional view taken along line 2A,4A-2A,4A shownin FIG. 1, showing the seat skin (i.e., trim cover) of the structure ofwadded-up seat trim cover, according to another embodiment (Embodiment2) of the present invention; FIG. 4B to FIG. 4D are sectional viewsexplaining the process of backing a skin member with first and secondwadding members prior to the sewing process, and particularly FIG. 4Bshows the portions to be bonded together; FIG. 5A is a schematic viewillustrating the first sewn portion in the structure of wadded-up seattrim cover, according to the other embodiment (Embodiment 2) of thepresent invention; and FIG. 5B is a schematic view illustrating thesecond sewn portions in the structure of wadded-up seat trim cover,according to the other embodiment (Embodiment 2) of the presentinvention.

Embodiment 2 will be described with reference to FIGS. 4A to 4D andFIGS. 5A and 5B. The components identical to those of Embodiment 1 areindicated by the same reference numbers and will not be described. Onlythe components characterizing Embodiment 2 will be described in themain.

In Embodiment 1, the skin member is backed with two wadding members(i.e., first and second wadding members). In Embodiment 2, the skinmember is backed with one wadding member only.

The center trim cover piece 22 adjacent to the left trim cover piece 24is composed of a skin member 22 a and a wadding member 22 b, laid one onthe back of the other, from the upper surface (i.e., seat cushionsurface) in the order mentioned. Like the center trim cover piece, theleft trim cover piece 24 is composed of a skin member 24 a and a waddingmember 24 b, laid one on the back of the other, from the upper surfacein the order mentioned.

The wadding member 22 b of the center trim cover piece is shorter thanthe skin member 22 a and is positioned below the skin member. A portion22 af of the skin member, which is longer than the wadding member 22 b,extends in the widthwise direction (to the left) beyond the end 22 bf ofthe wadding member, and does not overlap the wadding member.

At the position where the skin member 22 a of the center trim coverpiece 22 overlaps the wadding member 22 b, the skin member is bonded tothe wadding member at a prescribed distance (i.e., distance Y) from theend 22 bf of the wadding member, thereby forming a bonded portion 30.

The portion 22 af of the skin member, which does not overlap the waddingmember and extends from the end 22 bf of the wadding member in aprescribed distance (i.e., distance X1), is bent along the end of thewadding member in the direction of an arrow shown in FIG. 4B . Theportion 22 af, which is remote from the end of the skin member by aprescribed distance, is a bent-back portion 22 af′. Then, the portion 22af of the skin member is bent downward in the direction of the arrowshown in FIG. 4C. Two portions 22 af of the skin members 22 and 24 ofthe center and left trim cover pieces are overlapped (see FIG. 4D).

Next, the overlapped portions 22 af of the center and left trim coverpieces 22 and 24 are sewn below the wadding member 22 b, forming a firstsewn portion 31 (see FIG. 5A).

At the first sewn portion 31, the ends of the center and left trim coverpieces 22 and 24 (more precisely, the ends of the skin members 22 a and24 a) are bent back to the back of each trim cover. Then, the skinmembers 22 a and 24 a of the center and left trim cover pieces are sewntogether at the parts overlapped by the bending back (see FIG. 5A), andclamp the first sewn portion 31. Two second sewn portions 32 are therebyformed (see FIG. 5B).

The trim cover pieces 22 and 24 have been sewn together. Therefore, asseen from FIG. 5B, the resultant first and second sewn portions 31 and32 of the trim cover pieces (i.e., center and left trim cover pieces 22and 24) are formed at positions below the upper surface (i.e., surfaceof the seat cushion) by the sum of the thickness of the skin member andthe thickness Z of the wadding member. The sum of the thickness of theskin member and the thickness Z of the wadding member is approximatelyequal to the thickness of the wadding member. As a result, a groove Shaving depth approximately equal to the thickness Z of the waddingmember is provided between the trim cover pieces 22 and 24. The firstand second sewn portions 31 and 32 exist on the bottom of the groove S.

Since the first and second sewn portions 31 and 32 exist on the bottomof the groove S positioned below the upper surfaces of the trim coverpieces 22 and 24, the sewn portions would not hitch or rub the occupantas he sits or move on the seat, and the sewn portions would not beunraveled or severed. Further, the second sewn portions 32, which existon the bottom of the groove S, are seen from the upper surface of thetrim cover, the trim cover (wadding-up seat trim cover) can acquire agood outer appearance.

Moreover, the trim cover need not have core members, and the number ofcomponents does not increase.

The groove S is provided between two trim cover pieces 22 and 24 in thefirst and second sewing steps only, and the first and second sewnportions 31 and 32 are positioned on the bottom of the groove. The trimcover (wadding-up seat trim cover) that has sewn portions neitherunraveled nor severed and has a good outer appearance can bemanufactured by a simple method having a few steps, without usingadditional components such as core members.

As has been described above, this invention can provide a wadded-up seattrim cover having a good outer appearance and sewn portions neitherunraveled nor severed, without increasing the number of components.

Further, this invention can manufacture a wadded-up seat trim coverhaving a good outer appearance and sewn portions neither unraveled norsevered, made in a simple method having a few steps.

The embodiments have been described to explain this invention, and arenot intended to limit the scope of the invention. Accordingly, variouschanges and modifications may be made within the spirit or scope of thisinvention, and are of course included in this invention.

Each embodiment of the invention, described above, is a trim cover(wadded-up seat trim cover) for the seat cushion of the vehicle seat.The trim cover can be applied to the trim cover for the seatback or headrest of the vehicle seat. More specifically, the components of a trimcover for covering the seatback or head rest may be bonded and sewn bythe method according to this invention, thereby making a groove in thetrim cover and decorative sewn portions, lying on the bottom of thegroove, neither unraveled nor severed.

INDUSTRIAL APPLICABILITY

This invention is applied to the vehicle seat for use in buses, cars andaircraft. Its use is not limited to the vehicle seat, however. Theinvention can be applied also to a seat having a wadded-up seat trimcover, such as a seat for use in offices, public halls, theaters, moviehouses, sport facility.

Reference Marks in the Drawing

-   10 vehicle seat-   12 seat cushion-   12-1 seat pad-   20 trim cover-   22,24 center or left trim cover piece of the seat cushion-   22 a, 24 a skin member-   22 b, 24 b wadding member-   22 b-1, 24 b-1 first wadding member-   22 b-2, 24 b-2 second wadding member-   30 bonded portion-   31 first sewn portion-   32 second sewn portion(s)-   S groove

1. A structure of wadded-up seat trim cover for covering a seat pad,having a plurality of trim cover pieces sewn together at one end, eachcomposed of a wadding member and a skin member backed with the waddingmember, the structure comprising: a bonded portion formed by bonding theskin member to the wadding member made shorter than the skin member, ata position remote, by a prescribed distance, from the end of the waddingmember overlapping the skin member; a first sewn portion formed bybending that portion of the skin member, which does not overlap thewadding member, along the end of the wadding member and then by sewingthe portions of the adjacent skin members together below the adjacentwadding members; and second sewn portions formed by bending each end ofthe adjacent skin member to the back of the trim cover piece at thefirst sewn portion and then by sewing the adjacent skin members togetherat overlapping portions that clamp the first sewn portion.
 2. Thestructure according to claim 1, wherein the wadding member is composedof first and second wadding members, the bonded portion is formed bybonding the skin member to the first wadding member made shorter thanthe second wadding member and the skin member and clamped between theskin member and the second wadding member at a position remote, by aprescribed distance, from the end of the first wadding member; the firstsewn portion formed is by first bending that portion of the skin member,which does not overlap the first wadding member, along the end of thefirst wadding member, then overlapping the skin member on the secondwadding member, further bending the skin member together with the secondwadding member downward, and finally sewing the skin member and thesecond wadding member together below the first wadding member; and thesecond sewn portions are formed by bending back the ends of the skinmember and second wadding member to the back of the trim cover piece atthe first sewn portion and then by sewing the ends of the skin memberand the second wadding member together at overlapping portions thatclamp the first sewn portion.
 3. The structure according to claim 2,wherein the first wadding member is thicker than the second waddingmember.
 4. A method of manufacturing a wadded-up seat trim cover forcovering a seat pad, having a plurality of trim cover pieces sewntogether at one end, each composed of a wadding member and a skin memberbacked with the wadding member, the method comprising: a bonding step ofbonding the skin member to the wadding member made shorter than the skinmember, at a position remote, by a prescribed distance, from the end ofthe wadding member overlapping the skin member, thereby forming a bondedportion; a first sewing step of bending that portion of the skin member,which does not overlap the wadding member, along the end of the waddingmember and then sewing the adjacent trim over pieces below the adjacentwadding members, thereby forming a first sewn portion; and a secondsewing step of bending each end of the adjacent skin members to the backof the trim cover piece at the first sewn portion and then sewing theadjacent skin members together at overlapping portions that clamp thefirst sewn portion, thereby forming second sewn portions.
 5. The methodaccording to claim 4, wherein the wadding member is composed of firstand second wadding members, the bonding step is to bond the skin memberto the first wadding member made shorter than the second wadding memberand the skin member and clamped between the skin member and the secondwadding member, at a position remote, by a prescribed distance, from theend of the first wadding member, thereby forming a bonded portion; thefirst sewing step is to bend that portion of the skin member, which doesnot overlap the first wadding member, along the end of the first waddingmember, to overlap on the second wadding member, and then to sew theskin member and the second wadding member below the first waddingmember, thereby forming a first sewn portion; and the second sewing stepis to bend back the ends of the skin member and second wadding member tothe back of the trim cover piece at the first sewn portion and then tosew the ends of the skin member and second wadding member together atoverlapping portions that clamp the first sewn portion, thereby formingsecond sewn portions.
 6. The method according to claim 5, wherein thefirst wadding member is thicker than the second wadding member.